(1) Field of the Invention
The present invention pertains to a housing of an electric device that is specifically designed to direct liquid dropped onto the housing over an exterior surface of the housing and away from electrical components and vent openings of the device. More specifically, the present invention pertains to a housing of an electrical device that is provided with a shelf that covers over electrical components projecting from the housing and is provided with an annular flange and an annular diverging portion of the housing exterior surface that direct liquid by gravitation away from electrical components projecting from the housing and vent openings of the housing.
(2) Description of the Related Art
Electric motors that are employed in powering water pumps of home appliances, such as clothes washers and dish washers, are often subjected to a humid environment in use. This is particularly true where the construction of the home appliance requires that the electric motor be positioned with its drive shaft oriented vertically to drive a water pump of the appliance positioned above the motor. Any leakage of the pump will often result in water dropping down onto the electric motor. In addition, the motor driving the water pump in the enclosed environment of the appliance will often result in moisture condensing on the motor housing. Should the moisture find its way to the electrical connections of the electric motor or finds its way to the interior of the motor through the motor housing vent openings, short circuiting of the motor could occur or the user of the appliance could receive an electric shock.
Drip pans and gutter-style shields have been employed in the prior art to avoid the problem of leakage from an appliance water pump reaching an electric motor positioned below the pump. The drip pan or shield would be positioned below the water pump and above the motor powering the pump to prevent any leakage from the water pump reaching the motor. However, use of the drip pan or shield had the disadvantage of adding additional component parts to the appliance construction, thus increasing the appliance cost. In addition, use of the drip pan or shield required additional space in the appliance interior to accommodate the drip pan which reduced the space available for the clothes washing or dish washing compartment of the appliance.
What is needed to overcome the above described disadvantages of prior art electrical appliance motors positioned below water pumps is a way of directing liquid away from the electrical connections and vent openings of the motor without adding additional parts to the assembly of the appliance.
The present invention pertains to a fluid management system incorporated into the construction of a housing of an electric motor that directs liquid by gravitation away from the electrical connections and vent openings of the motor housing. Although the invention is described as being incorporated into the housing of an electric motor, it is equally well suited for use with housings of other types of electrical devices.
The preferred embodiment of the invention is employed on a housing of an electric motor that is positioned with its drive shaft oriented vertically in use. The electric motor housing is basically comprised of a generally circular top wall, a generally circular bottom wall spaced axially below the top wall, and a generally cylindrical side wall that extends axially between the top wall and the bottom wall. Together the top wall, the side wall and the bottom wall enclose an interior volume of the motor housing that contains the electric motor. In the preferred embodiment, the motor housing is constructed in two pieces with the top wall of the housing forming one piece and the side wall and bottom wall of the housing forming the second piece.
The top wall has a shaft opening at its center and the motor shaft projects upwardly through the shaft opening. A cooling fan is mounted on the projecting end of the motor shaft. In use, the fan is positioned between the motor housing and the water pump of the appliance positioned above the motor. The fan has a circular disk at its top, and the blades of the fan extend radially across the bottom surface of the disk. Thus, the disk of the fan provides some shielding of the electric motor from water leaking from the water pump positioned above the motor.
The top wall of the housing has a circular, peripheral edge with an annular flange that extends radially outwardly from the edge. The flange has opposite top and bottom surfaces, and the bottom surface of the flange seats against a top edge of the housing sidewall when the housing top piece is assembled to the housing bottom piece. The top wall flange also has an annular lip that projects axially downward from the bottom surface of the flange. The annular lip is dimensioned so that it is spaced radially outwardly from the housing side wall when the top piece of the housing is assembled to the bottom piece. This positioning of the annular lip allows it to direct liquid leaked onto the housing top wall from the pump over the exterior surface of the top wall and downwardly over the lip where the liquid will drip from the annular lip.
The top wall or the top piece of the housing is also provided with a shelf or ledge that projects outwardly from the peripheral edge of the top wall. The shelf is positioned axially above an electrical connector opening provided in the side wall of the housing. The shelf has opposite side edges that extend radially outwardly to a distal end of the shelf. A ridge projects axially upwardly from the shelf distal edge and functions as a gutter that directs any moisture that flows over the shelf top surface away from the shelf distal edge and toward the side edges of the shelf. A pair of side panels extend axially downwardly from the shelf side edges and together the shelf bottom surface and the pair of side panels completely cover the electric connectors of the electric motor projecting from the side wall of the motor housing. Any liquid that gravitates over the top wall of the housing onto the top surface of the shelf is directed by the shelf ridge and the shelf side panels downwardly around the electric connectors of the motor.
The bottom piece of the motor housing is provided with a plurality of vent openings in the area of the motor housing where the bottom wall joins with the housing side wall. The plurality of vent openings are spatially arranged around the peripheral edge of the bottom wall. To prevent any liquid that gravitates downwardly across the motor housing from entering the vent openings, a portion of the exterior surface of the housing side wall diverges radially outwardly as it extends axially downwardly toward the vent openings. The diverging portion of the side wall exterior surface extends downwardly to an underside surface of the side wall that is positioned immediately above the vent openings of the housing. The underside surface extends axially downwardly as it extends radially outwardly away from the vent openings toward the side wall exterior surface. Because the underside surface extends axially downwardly as it extends outwardly away from the vent openings, any liquid gravitating downwardly across the exterior surface of the motor housing side wall is caused to drip from the outer edge of the housing where the side wall joins with the underside surface and thereby drips away from the motor housing and away from the vent openings.
The electric motor housing of the invention constructed in the manner discussed above directs any liquid that drips downwardly onto the housing to drain downwardly across the exterior surface of the housing and away from the motor electrical connections and the housing vent openings, thereby eliminating the problem of liquid potentially short circuiting the motor.